Hopper magnet



Oct. 8, 1957 R. F. MERwlN ETAL 2,808,932

f HOPPER MAGNET Filed March 30, '1953 f "'nvnlf Rose/WF. MeRw' RONALD o. HOFF United States Patent C HGPPER MAGNET Robert F. Merwin and Ronald C. Hoff, Erie, Pa., assignors to Eriez Manufacturing Company, Erie, Pa., a corporation of Pennsylvania Application March 30, 1953, Serial No. 345,527

3 Claims. (Cl. 209-223) This invention relates generally to magnetic separating devices.

In the process and treating of material during manufacturing processes, it is frequently undesirable to have tramp iron and other contamination present in the material being handled because of adverse affect on the machine handling the material and because of the undesirable alect of the tramp iron on the material itself and its use. One example of a location where the presence of tramp iron in material is objectionable is where the material is fed into a hopper on the processing machine. Plate magnets have been tried but they have been unsuccessful because the material could not be caused to pass in close proximity to the magnetic elements and the material was not evenly distributed. When the material to be separated was choke fed, that is, a hopper was filled with the material to be separated and the material allowed to flow over the magnets, the desired results of separation were not accomplished with prior designs of magnets.

It is, accordingly, an object of this invention to overcome the above and other defects and disadvantages in prior machines and more particularly an object to provide a magnetic separating device particularly suitable for use in hoppers.

Another object of the invention is to provide a magnetic separating device wherein the material flowing past the separating device will be subjected to magnetic fields throughout the material.

Another object of the invention is to provide a magnetic separating device which in itself controls the depth of flow of material over and through it.

Another object of the invention is to provide a magnetic separating device which is economical in manufacture and simple in construction.

With the above and other objects in view, the present invention consists of the combination and arrangement of parts hereinafter more fully described, illustrated in the accompanying drawing, and more particularly pointed out in the appended claims, it being understood that changes may be made in the forme, size, proportions, and minor details of construction without departing from the spirit or sacricing any of the advantages of the invention.

In the drawing:

Fig. l is an end view of the hopper magnet according to the invention;

Fig. 2 is a side view of our novel hopper magnet;

Fig. 3 shows a variation of shape of disk; and

Fig. 4 shows our magnet disposed in a hopper.

Now with more specific reference to the drawing, we show the magnetic sections 1, 2, 3, 4, and 5 being cylindrical in cross section and made of a material having a high magnetic strength such as the aluminum nickel cobalt alloy defined by the trademark Alnico 5. The cylindrical magnets have hard wood cores 6, 7, 8, 9, and 10, respectively. The magnetic cores 6 and 7 are held in spaced relation by the steel disks or plates 11 and 12. which are preferably made of iron.

2,808,932 Patented Oct. 8, 1957 The bolt 13 is made of Ysome non-magnetic material such as brass or stainless steel and the entire assembly is held together by the hexagonal nuts 14 and 15 which engage the ends of the disks 12. Washers 16 may be provided to facilitate the assembly process if desired. It will be noted that the disks 12 are larger in diameter than the disks 11 and extend past the ends thereof.

One method found desirable for assembling the hopper magnet comprises inserting the core 10 in the magnet 5, then a plate 11 is put in either end of the magnet castin-g, and this assembly is held together by a tie pin, a piece of Wire, or similar device while the magnet is being charged. The magnet is charged by subjectingV it to a high density iield such as that produced by a large solenoid excited by a strong direct current. Y

After several of these sub-assemblies have been charged so that when put end to end they make up the desired length of magnet, they are mounted as shown on the non-magnetic tie rod or bolt 13 with plates 12 disposed between each sub-assembly.

First the hexagonal nut 14 is attached to the rod by means of the thread. The Washer 16 is then put on the rod and the magnetic sub-assembly composed of disks 11, magnet 5, and core 10 is put on the rod. Then another disk 12 is put on the rod and the magnetic sub-assembly is installed. The plates 11 and 12 all have substantial thickness as shown. The procedure of assembling the magnetic sub-assemblies is repeated until the desired length of magnetic unit is obtained or until the rod 13 is lled to its end. Then the hexagonal nut 14 is threadably attached to the rod and the unit is complete.

It is extremely important that like or repelling poles of the magnets of the sub-assemblies be placed adjacent to each other as indicated by the letters N and S in the drawing. This, in additionto the fact that the steel disks 11 and 12 are of different diameters, causes two concentrated flux fields, one at the periphery of the small plates and one at the periphery of the large plates. This, in elect, divides the ux field and results in a magnetic circuit and iield Which is extremely eicient in the even distribution of flux lines of force around the periphery of the plates. A flux concentration is provided at 20 and another at 21 around the periphery of each disk 11 and each disk 12. The available magnetic linx is distributed throughout the desired area. Because the plates are effectively tapered, two major magnet lields are provided at the circumferences of the two disks as shown at 20 and 21.

Because of the fact that the magnet is made up of increments of the magnetic assembly, including the disks or elements 11 and 12, the magnetic assembly can be made of any desired length by selecting a longer tie rod and adding additional magnetic units. The disks can be made in other than round shape to make the unit more readily adaptable to use in ducts. For example, the disks could be polygonal in shape as shownv in Fig. 3. In Fig. 3, we show how the shape ofthe disks 101 can be varied to suit particular applications and in Fig. 4, we show our magnet device 1 arranged in a hopper.

The magnetic assembly shown in Fig. 2 is particularly Y adapted to be disposed in a hopper Where the material to be separated from tramp iron may be fed. In its position in the hopper, the magnet will collect the tramp iron from the material flowing through it. When a considcrable amount of iron is accumulated on the disks 11 and 12, the magnetic unit can be lifted out of the hopper and the tramp iron and other ferrous material can be wiped ofi the disks with a rag or other suitable means. Because of the particular shape of the assembly, it can be easily supported in the conventional type of hopper merely by setting it in place.

In the'foregoing specification, we have set forth the invention lin its preferred practical forms but we are aware that the structure shown is capable of modification within a range of equivalents without departing from the invention which is to be understood is broadly novel asis commensuratewith the appended claims.

' What we claim is:

'1. A magnetic separator comprising -a plurality of tubular shaped permanent magnets disposed in end to end relationship with like poles of each magnet adjacent like poles of an adjacent magnet, two small plates of magnetic material having substantial and constant thickness disposed between each adjacent magnet ends, and a large plate of magnetic'material having, Substantial and constant thickness disposed between said small plates.

2. A magnetic separator comprising a plurality of permanent magnets generally cylindrical in shape and disposed in axial alignment with like poles adjacent each other, two plates of magnetic material having substantial thickness comprising a pair of plates disposed bel tween each two adjacent magnets, said two plates extending outward beyond the edges of said magnets a substantial distance, a plate made of magnetic material having substantial thickness disposed between each said pair of plates and extending outward beyond the edges thereof a substantial distance, and magnetic fields of relatively high strength being concentrated adjacent the edges of said plates remotest from said magnets whereby magnetic material from material passing between said plates transversely of said device is attracted by said fields.

3. The 'magneticY separator recited in claim 2 wherein said plates are generally concentrically disposed and said magnets are disposed at the center of said plates.

References Cited in the tile of this patent FOREIGN PATENTS 

